JP2003254347A - Bearing unit with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing unit with a sensor improved in detection accuracy by eliminating the necessity of forming a large air gap. <P>SOLUTION: This bearing unit with a sensor is provided with a shaft member 1, a bearing member 2 arranged outside of the shaft member 1 in the condition that they are brought in contact with each other, a magnetic pulser 3 provided in the shaft member 1 and having a magnetic characteristic different each other, and a magnetic sensor 5 provided in the bearing member 2 to detect pulses from the magnetic pulser 3. The magnetic pulser 3 has a magnetization pattern alternately magnetized in the circumferential direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor-equipped bearing unit, and more particularly to a sensor-equipped bearing unit having a magnetic pulser on one side and a magnetic sensor on the other side.

Bearing units with sensors are, for example,
In railway vehicles and automobiles, it is used to support an axle or a rotary shaft that transmits rotation to the axle and detect the rotational speed of the shaft.

[0003]

2. Description of the Related Art In order to detect the rotational speed of a shaft, a rolling bearing having an outer ring, an inner ring and a plurality of rolling elements arranged between them, and a rolling bearing provided on one of the outer ring and the inner ring and circumferentially A rolling bearing unit with a sensor is used, which includes a magnetic pulser which has different magnetic properties alternately at equal intervals, and a sensor device which is provided on the other side and has a magnetic sensor, a sensor support member and a sensor cover. .

[0004]

In the above-mentioned conventional bearing unit with a sensor, in consideration of the accuracy and the radial clearance of each component, the magnetic pulser and the magnetic sensor are prevented from coming into contact with each other, and the radial unit during rotation is provided between them. It is necessary to have a predetermined air gap in consideration of the variation in the gap. However, if the magnetic flux density of the magnetizing ring is low or the sensitivity of the magnetic sensor is low, there is a problem that it becomes difficult to secure a necessary air gap.

The object of the present invention is to solve the above problems,
It is an object of the present invention to provide a bearing unit with a sensor that does not require a large air gap and therefore has high detection accuracy.

[0006]

A bearing unit with a sensor according to the present invention has a shaft member, a bearing member arranged in contact with the outside of the shaft member, and one of the shaft member and the bearing member. A magnetic pulser provided and alternately having different magnetic characteristics, and a magnetic sensor provided on the other side and detecting a pulse from the magnetic pulser are provided.

The bearing member may be a static pressure bearing or a dynamic pressure bearing that rotatably supports the shaft member, or a slide bearing when the shaft member moves in the axial direction. Good.

As the magnetic sensor, a Hall element sensor, a magnetic resistance (MR) element sensor or the like is used.

According to the bearing unit with a sensor of the present invention, since the shaft member and the bearing member are in contact with each other or are supported in a stable state with a small gap, the variation in the radial gap during rotation is extremely small. The distance between the magnetized surface of the magnetic pulser and the magnetic sensor can be reduced, and as a result, the relative movement amount of the bearing member with respect to the shaft member can be detected with high accuracy. Moreover, the number of constituent parts can be reduced as compared with the conventional bearing unit with a sensor which is mainly a rolling bearing.

When the magnetic sensor is provided on the bearing member, for example, a cylindrical sensor support member having a through hole for accommodating the magnetic sensor is used, and this is fitted into the outer diameter of the bearing member, and the magnetic sensor is mounted on the magnetic pulser. The bearing member may be provided with a hole to face it. When the magnetic sensor is provided on the shaft member, for example, a magnetic sensor housing recess may be provided on the outer diameter of the shaft member, and the magnetic sensor may be fitted and fixed in the recess. In any case, the magnetic sensor and the magnetic pulser may be opposed to each other in the radial direction or may be opposed to each other in the axial direction.

The magnetic pulser may have a magnetization pattern magnetized alternately in the circumferential direction. By doing so, information such as the number of rotations, the rotation direction, and the rotation angle can be obtained.

The magnetic pulser may have a magnetized pattern magnetized alternately in the axial direction. This makes it possible to obtain information such as the amount of movement in the axial direction, the moving direction, and the moving speed in the axial direction.

In order to form a magnetic pulser having a circumferential magnetizing pattern, for example, a belt-shaped magnetized body is manufactured, and the magnetized body is flush with an annular groove provided on the outer diameter of the shaft member or the inner diameter of the bearing member. It may be fitted and glued so that Also,
In order to form a magnetic pulser having a magnetic pattern in the axial direction, for example, a belt-shaped magnetized body is manufactured, and the magnetized body is made flush with the axial groove provided on the outer diameter of the shaft member or the inner diameter of the bearing member. It can be fitted in and glued.

In both cases of forming a magnetic pulser having a circumferential magnetization pattern and forming a magnetic pulser having an axial magnetization pattern, the shaft member is a magnetic body, and the magnetic pulser is a shaft. You may make it formed by magnetizing the outer diameter of a member. By doing so, a belt-shaped magnetized body is not necessary, and a bearing unit with a sensor having a simpler structure can be obtained.

[0015]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following description, the left and right shall refer to (a) of FIG. 1 and (a) of FIG.

FIG. 1 shows a first embodiment of a bearing unit with a sensor according to the present invention.

A sensor-equipped bearing unit according to the present invention shown in FIG. 1 includes a cylindrical shaft member (1) and a cylindrical bearing which is arranged in contact with the outside of the shaft member (1) and is fixed to a fixing portion (not shown). The member (2), the magnetic pulser (3) provided on the outer diameter of the shaft member (1) and having alternately different magnetic characteristics, and fitted in the annular groove provided on the outer diameter of the bearing member (2). Cylindrical sensor support member (4) and sensor support member (4)
And a magnetic sensor (5) held by the magnetic pulser (3) for detecting the pulse from the magnetic pulser (3).

In the magnetic pulser (3), a magnetized body in which N poles and S poles are alternately and equidistantly formed in a band shape is provided in an annular groove provided on the outer diameter of the shaft member (1). It is formed by being fitted and fixed with an adhesive or the like.
The outer peripheral surface of the magnetic pulser (3) is flush with the outer peripheral surface of the shaft member (1) or has a slightly smaller diameter. The magnetized body has flexibility such as a rubber-like elastic body, and can be obtained, for example, by cutting a magnetized sheet-shaped rubber magnetic body into a band shape.

The sensor support member (4) has a magnetic sensor housing through hole (4a) at one location on the circumference. The outer diameter of the sensor support member (4) is smaller than the outer diameter of the bearing member (2). At the part of the bearing member (2) corresponding to the magnetic sensor housing through hole (4a), attach the magnetic sensor (5) to the magnetic pulser.
A hole (2a) is provided to face (3).

The magnetic sensor (5) is a sensor support member (4).
By being fitted in the magnetic sensor housing through hole (4a), the magnetic pulser (3) is opposed to the magnetic pulser (3) with a slight gap from the radial outside.

According to the sensor-equipped bearing unit of the first embodiment, the change in the magnetic characteristics of the magnetic pulser (3), which is relatively rotated with the rotation of the shaft member (1), changes in the magnetic sensor (5). This signal is sensed, and this signal is transmitted through a processing circuit (not shown). As a result, information such as the number of rotations, the rotation direction, and the rotation angle can be obtained.

A second embodiment of the bearing unit with a sensor according to the present invention shown in FIG. 2 is a slide bearing type, which is a cylindrical shaft member (11), and is arranged in contact with the outside of the shaft member (11) and has a fixed portion ( Bearing member (12) fixed to (not shown)
And a magnetic pulser (13) provided on the shaft member (11) and having alternately different magnetic characteristics, and a cylindrical sensor support member fitted in an annular groove provided on the outer diameter of the bearing member (12). (14) and a magnetic sensor (15) which is held by the sensor support member (14) and detects a pulse from the magnetic pulser (13).

The magnetic pulser (13) has a magnetized body formed in a strip shape such that the N poles and the S poles are alternately arranged at equal pitches. The magnetized body is provided in the axial groove of the shaft member (11). It is formed by being fitted into (11a) and fixed with an adhesive or the like. The outer diameter of the magnetic pulser (13) is the same as or slightly smaller than the outer diameter of the shaft member (11).

The sensor support member (14) is a magnetic pulser.
It has a magnetic sensor housing through hole (14a) at a position facing (3). The outer diameter of the sensor support member (14) is smaller than the outer diameter of the bearing member (12).

The magnetic sensor (15) is fitted into the magnetic sensor housing through-hole (14a) to provide a magnetic pulser.
They are opposed to each other with a slight gap from the outside in the radial direction of (13).

According to the sensor-equipped bearing unit of the second embodiment, the change in the magnetic characteristics of the magnetic pulser (13), which is relatively moved along with the axial movement of the shaft member (11), is
The signal is detected by the magnetic sensor (15), and this signal is transmitted through a processing circuit (not shown). This makes it possible to obtain information such as the amount of movement in the axial direction, the moving direction, and the moving speed in the axial direction.

In the first and second embodiments, the materials of the shaft members (1) (11) and the bearing members (2) (12) are not particularly limited as long as they are excellent in wear resistance. Although not a thing, the shaft member (1) (11) is made a magnetic body, and the magnetic pulser (3) (13) is not attached to the magnetized body, but the shaft member (1) (11) It can also be formed by magnetizing the outer diameter. Alternatively, a magnetic material such as a rubber magnetic material may be formed in the annular groove or the axial groove (11a) provided in the shaft members (1) and (11) and then magnetized.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a bearing unit with a sensor according to the present invention, in which (a) is a part (bearing member).
Is a side view with a cutout, and (b) is a sectional view taken along line bb of (a).

FIG. 2 is a view showing a second embodiment of the sensor-equipped bearing unit according to the present invention, in which (a) is a part (bearing member).
Is a side view with a cutout, and (b) is a sectional view taken along line bb of (a).

[Explanation of symbols]

(1) (11) Shaft member (2) (12) Bearing member (3) (13) Magnetic pulser (5) (15) Magnetic sensor

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Claims (4)

[Claims] 1. A shaft member, a bearing member arranged in contact with the outside of the shaft member, a magnetic pulser provided on either one of the shaft member and the bearing member and having different magnetic characteristics alternately, and the other. A bearing unit with a sensor, which is provided and has a magnetic sensor that detects a pulse from a magnetic pulser. 2. The bearing unit with a sensor according to claim 1, wherein the magnetic pulser has a magnetizing pattern magnetized alternately in the circumferential direction. 3. The bearing unit with a sensor according to claim 1, wherein the magnetic pulser has a magnetizing pattern magnetized alternately in the axial direction. 4. The bearing unit with sensor according to claim 2, wherein the shaft member is a magnetic body, and the magnetic pulser is formed by magnetizing the outer diameter of the shaft member.